The
Lockheed P-38L-5LD "Lightning"
was being ferried from Tullahoma,
Tennessee, to its home base in Texas
following its participation in an air
show. During descent into the Greenwood,
Mississippi area for refueling, the left
engine backfired, ran roughly, and the
cockpit filled with thick smoke. With
reduced cockpit visibility, and a need to
get the aircraft on the ground as soon as
possible, the pilot chose a cotton field
for a forced landing. Postcrash
examination of the left engine revealed
the supercharger sustained an internal
compressor wheel failure that shot
compressor blade pieces through the
supercharger housing and the fuel feed
line. High pressure 100 octane fuel
spewed inside the left engine nacelle,
ignited, and caused the in-flight fire.

The
National Transportation Safety Board
determines the probable cause(s) of this
accident as follows.

the
failure and uncontained separation of
supercharger impeller blades for
undetermined reasons during normal
descent, resulting in a punctured fuel
line and the subsequent in-flight engine
fire and emergency descent and forced
landing to a farm field. (full NTSB narrative)

On June 25, 2001,
about 0920 central daylight time, a
Lockheed P-38L-5LD Lightning, N25Y,
registered to a private individual,
operating as a Title 14 CFR Part 91
personal flight, executed an emergency
landing to a cotton field due to a fire
in the left engine in the vicinity of
Greenwood, Mississippi. Visual
meteorological conditions prevailed and
no flight plan was filed. The aircraft
received substantial damage and the
commercially-rated pilot, the sole
occupant, was not injured. The flight
originated from Tullahoma, Tennessee,
about 1 hour 20 minutes before the
accident.

According to the pilot, during in-range
descent to Greenwood-Leflore Airport, the
left engine backfired, started running
roughly, and the cockpit filled with
thick black smoke. When the canopy
release was eventually activated, he
observed that the left engine was on fire
and trailing flame was consuming the
carburetor air intake scoop and the
aluminum skin between the left reserve
fuel tank and the left engine cowling.
Due to the severity of the fire he
decided to put the aircraft on the
ground, gear up, as soon as possible. The
site was a cotton field about 5 miles
southwest of the airport.

According to an FAA inspector,
examination of the wreckage site revealed
that after touchdown, the aircraft slid
about 600 feet in soft dirt at an angle
to the furrows of cotton plants.
Examination of the aircraft revealed the
smoke and flames emanated from a hole in
the rear area of the left engine
supercharger housing. Both propellers had
separated, the left engine upper nacelle
and left inboard fuel tank were burned
extensively, both engine lower nacelles,
the right vertical stabilizer, and the
underside of the fuselage sustained major
ground impact damage.

According to the crew chief/mechanic for
N25Y, a more thorough postcrash
examination of the left engine components
revealed failure of 4 to 5 supercharger
compressor blades. The helix shaped,
centrifugal compressor blades failed from
the hub, outward, about 1/3 span. When
the high rpm operating impeller blades
fractured and separated, they penetrated
the supercharger housing and a 3/4-inch
diameter fuel feed hose to the
carburetor, causing 100 octane fuel at 17
to 20 psi to shower the engine inside the
nacelle, thus the in-flight fire.